相关疑难解决方法(0)

我正在使用AVFoundation构建应用程序.

就在我打电话[assetWriterInput appendSampleBuffer:sampleBuffer]的 - (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection-方法.

我操纵样本缓冲区中的像素(使用pixelbuffer来应用效果).

但是客户希望我在框架上输入文本(timestamp&framecounter),但我还没有找到办法.

我试图将samplebuffer转换为Image,在图像上应用文本,然后将图像转换回samplebuffer,但是

CMSampleBufferDataIsReady(sampleBuffer)

失败.

这是我的UIImage类别方法:

 +  (UIImage *) imageFromSampleBuffer:(CMSampleBufferRef) sampleBuffer
    {
    CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);

    CVPixelBufferLockBaseAddress(imageBuffer,0);

    uint8_t *baseAddress = (uint8_t *)CVPixelBufferGetBaseAddress(imageBuffer);
    size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);
    size_t width = CVPixelBufferGetWidth(imageBuffer);
    size_t height = CVPixelBufferGetHeight(imageBuffer);


    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef newContext = CGBitmapContextCreate(baseAddress, width, height, 8, bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);

    CGImageRef newImage = CGBitmapContextCreateImage(newContext);

    CGContextRelease(newContext);
    CGColorSpaceRelease(colorSpace);

    UIImage *newUIImage = [UIImage imageWithCGImage:newImage];

    CFRelease(newImage);

    return newUIImage;
    }

和

 - (CMSampleBufferRef) …